how to fix plastic intake...

I've got a broken intake off an LQ4. I'd like to repair it and powdercoat it. What has anyone had luck with? I don't think an epoxy / glue would hold up to 400 degree temps, but I'm wondering if JB weld will work or crack easily later on down the road?...

Forgot to mention. It looks like something big was dropped on it once. The cracks are not all the way around that bolt, it hinges back and forth under a lot of pressure. I cant pull it straight though - I'm wondering if I can put it in the freezer or unleash an upside-down can of compressed air onto it to get it cold and then gice that bolt a good smack with a hammer to get a clean brake all the way around. Other wise I'd have to push it up from the inside somehow to get all the cracks to sit flush and lay flat...

I don't need the intake, I have an LS1 intake already. I want to experiment on this one first before I coat my LS1 manifold, and I figure if I can fix it I could sell it when I'm done (if it turns out good).

I'd like to know how you coated your LS6 manifold. I was planning on washing it (of course) and then sticking it in the oven @ 400 until it stops smoking, letting it cool off and hitting it with some brake cleaner, heating it up again and shooting it hot. Or... mixing the powder with some acetone and shooting it wet out of a LPHV spray gun and let it dry for a day. I've shot some metal sample chips "wet" before and they turning out good looking... I haven't done any durrability testing on it yet though...

And you got me on the epoxy thing.. I meant something like gorrila glue vs JB weld. I've seen people use that stuff on exhaist manifolds, lol! Just wondering it there was something else.

I wouldn't mix with acetone, there are better options if you are playing with making liquid powder mixtures.

I don't take any of these GM "plastic" manifolds to 400 when coating. 375 is my limit.

You'll need the right gun, ain't gonna work with a EW hobby gun or anything like it with one of those diffusers on the end that blows the cloud everywhere but straight. Significantly different techniques involved compared to shooting parts cold.

Traditional JD Weld two part mix is good to 500 degree. That JB tube stuff you just pinch off and use is only good to 300 degrees. I'm not sure I'd be comfortable using any of the above to fix and coat if you plan to sell it, might come back to bite ya.

Best of luck.

Quote:

Originally Posted by 383mazda

I don't need the intake, I have an LS1 intake already. I want to experiment on this one first before I coat my LS1 manifold, and I figure if I can fix it I could sell it when I'm done (if it turns out good).

I'd like to know how you coated your LS6 manifold. I was planning on washing it (of course) and then sticking it in the oven @ 400 until it stops smoking, letting it cool off and hitting it with some brake cleaner, heating it up again and shooting it hot. Or... mixing the powder with some acetone and shooting it wet out of a LPHV spray gun and let it dry for a day. I've shot some metal sample chips "wet" before and they turning out good looking... I haven't done any durrability testing on it yet though...

And you got me on the epoxy thing.. I meant something like gorrila glue vs JB weld. I've seen people use that stuff on exhaist manifolds, lol! Just wondering it there was something else.

What would you recommend to fix the crack? I use a Gema OptiStar gun powder gun (I work as a powder coater, this isn't my hobby in the garage or anything). I only assumed 400 deg. because I heard they can take a little higher than that, 375 would work, I use a lot of IFS powder that cures at 340, some at 390.

If I can fix it I'm still going to PC the manifold and toss it in the showroom if it turns out good, then it's on to my LS1 intake for my car. Any pointers? I've shot hot a handful of times, I usually turn the powder down so I can watch each light layer gel, and I re apply until I get a smooth gelling layer...

I would just use that as a practice/display part. I've fixed small holes in these manifolds before then coated, but nothing like what you're dealing with.

You can cure a 390 powder at 375 by extending the cure schedule. The powder manufacturer will be able to tell you how much longer to cure it.

Yes, watch your cloud. Light, fast passes. Manifold will cool off much faster than a metal part, so have to work quickly. Don't worry about trying to get it all done in one round when first learning. If it cools to below flow out temps on you before you have full coverage just put it back in for a few minutes to get it back up to temp and continue.

If you don't have alot of experience flocking, I'd practice on some random metal parts first. Those you can strip if you screw up. Mess up one of these manifolds by melting a powder chunk on it and you've got a much bigger issue on your hands. Can't just dunk these in the chemical tank(or however you guys strip in your shop).

sounds good, I'm going to give it a shot... this truck manifold has a lot of nooks and crannies, I'll probably have to re heat it multiple time while shooting... The LS1 intake looks a lot simpler though. I'll post some pictures when I'm done.